A2DP doesn't require a chip at all, it's just a software protocol, Apple could have easily added it to any firmware since the orignial iPhone launched, they just chose not to.
Don't forget the 32GB iPhone and the 2 or so million people complaining about it being released so soon after they put the 3G out (which is why it'll probably cost $400).
Yeah, there was a review in one of the UK mac magazines a few months ago of bluetooth speakers/headphones and they all sounded rubbish. They concluded that BT stereo wasn't yet a mature or useful technology for most users. Still, why let that stop anyone complaining, eh?